Trench-Type Field Effect Transistor (Trench FET) With Improved Poly Gate Contact

Abstract

An integrated circuit (IC) device may include a plurality of trench-type field-effect transistors (trench FETs). Each trench FET may include a poly gate trench formed in an epitaxy region, a poly gate formed in the poly gate trench, a front-side poly gate contact, and a lateral gate coupling element (e.g., a lateral “strap”) extending over or adjacent, and in contact with, at least one surface of the poly gate formed in the trench and electrically connecting the poly gate to the front-side poly gate contact. The lateral gate coupling element may be formed from a material having a higher electrical conductivity than the poly gate, e.g., tungsten or other metal. The lateral gate coupling element may be at least partially located in the poly gate trench.

1 . An integrated circuit (IC) device, comprising:
 a plurality of trench-type field-effect transistors (trench FETs), each trench FET comprising:
 a poly gate trench formed in an epitaxy region; 
 a poly gate formed in the poly gate trench; 
 a front-side poly gate contact; and 
 a lateral gate coupling element extending over or adjacent at least one surface of the poly gate formed in the trench and electrically connecting the poly gate to the front-side poly gate contact. 
   
     
     
         2 . The device of  claim 1 , wherein each trench FET further comprises:
 a doped source region formed in the epitaxy region; and   a front-side source contact coupled to the doped source region.   
     
     
         3 . The device of  claim 1 , wherein the lateral gate coupling element is formed from a different material than the poly gate. 
     
     
         4 . The device of  claim 1 , wherein the lateral gate coupling element has a higher electrical conductivity than the poly gate. 
     
     
         5 . The device of  claim 1 , wherein the lateral gate coupling element comprises a metal. 
     
     
         6 . The device of  claim 1 , wherein the lateral gate coupling element comprises tungsten. 
     
     
         7 . The device of  claim 1 , wherein the lateral gate coupling element is at least partially located in the poly gate trench. 
     
     
         8 . The device of  claim 1 , wherein the lateral gate coupling element extends down to at least 25% of a depth of the poly gate trench. 
     
     
         9 . The device of  claim 1 , wherein the lateral gate coupling element extends down to at least 50% of a depth of the poly gate trench. 
     
     
         10 . The device of  claim 1 , wherein the lateral gate coupling element extends down to at least 75% of a depth of the poly gate trench. 
     
     
         11 . The device of  claim 1 , wherein the lateral gate coupling element extends over a top surface of the poly gate formed in the trench. 
     
     
         12 . The device of  claim 1 , wherein the lateral gate coupling element extends down into a cavity defined by poly material deposited in the trench. 
     
     
         13 . A field-effect transistor (FET), comprising:
 a poly gate trench formed in an epitaxy region;   a poly gate formed in the poly gate trench;   a front-side poly gate contact; and   a lateral gate coupling element extending over or adjacent at least one surface of the poly gate formed in the trench and electrically connecting the poly gate to the front-side poly gate contact.   
     
     
         14 . The FET of  claim 8 , further comprising:
 a doped source region formed in the epitaxy region; and   a front-side source contact coupled to the doped source region.   
     
     
         15 . The FET of  claim 8 , wherein the lateral gate coupling element is formed from a different material than the poly gate. 
     
     
         16 . The FET of  claim 8 , wherein the lateral gate coupling element has a higher electrical conductivity than the poly gate. 
     
     
         17 . The FET of  claim 8 , wherein the lateral gate coupling element comprises tungsten. 
     
     
         18 . The FET of  claim 8 , wherein the lateral gate coupling element is at least partially located in the poly gate trench. 
     
     
         19 . An electronic device, comprising:
 an integrated circuit (IC) device, comprising:
 a plurality of trench-type field-effect transistors (trench FETs), each trench FET comprising:
 a poly gate trench formed in an epitaxy region; 
 a poly gate formed in the poly gate trench; 
 a front-side poly gate contact; and 
 a lateral gate coupling element extending over or adjacent at least one surface of the poly gate formed in the trench and electrically connecting the poly gate to the front-side poly gate contact. 
 
   
     
     
         20 . A method of forming an integrated circuit (IC) structure including a plurality of trench-type field-effect transistors (trench FETs), the method comprising:
 forming a poly gate trench in an epitaxy region;   forming a poly gate in the poly gate trench;   forming a lateral gate coupling element extending over or adjacent, and coupled to, at least one surface of the poly gate;   forming a front-side poly gate contact coupled to the lateral gate coupling element; and   wherein the lateral gate coupling element forms an electrical connection between the poly gate and the front-side poly gate contact.   
     
     
         21 . The method of  claim 16 , wherein the lateral gate coupling element is formed from a different material than the poly gate. 
     
     
         22 . The method of  claim 16 , wherein the lateral gate coupling element has a higher electrical conductivity than the poly gate. 
     
     
         23 . The method of  claim 16 , wherein the lateral gate coupling element comprises tungsten. 
     
     
         24 . The method of  claim 16 , wherein the lateral gate coupling element is at least partially located in the poly gate trench. 
     
     
         25 . The method of  claim 16 , comprising:
 etching a top portion of the poly gate in the poly gate trench to define a recess in the poly gate; and   forming the lateral gate coupling element such that the lateral gate coupling element extends at least partially into the etched recess in the poly gate.